1. Field of the Invention
The present invention relates to improved clay coating formulations having particular utility in the field of carbonless copying. The formulations of the present invention may be utilized, for example, in the production of self-marking impact papers of the transfer or manifolding type wherein a first marking ingredient is carried on one sheet of paper for reaction with a second marking ingredient normally carried on a mating sheet of paper. More particularly, the invention relates to the use of particular inactive clayey materials in combination with an active clay such as an acid-leached bentonite-type clay to facilitate the production therefrom of coating slurries having high solids contents whereby the same may be coated on paper using a blade-coater to present a so-called receiver sheet of a carbonless copying system. High solids content coating slurries facilitate the "on machine" production of receiver sheets as the paper itself is made, thereby providing a "one step" operation by eliminating a subsequent paper coating step.